研究論文
溶融純銅と水蒸気との平衡
1974 年 46 巻 11 号 p. 993-999
詳細
1974 年 46 巻 11 号 p. 993-999
The equilibrium data in the reaction
H2O(g)=H2(g)+O(in liquid copper)
are very important for foundry practice of copper casting. Allen and Hewitt determined this equilibrium about fourty years ago, but the importance of this equilibrium is such that redetermination would be useful. In this study, the equilibrium constant has been obtained at the temperature of 1,150°C, 1,250°C and 1,350°C, and at a water vapour pressure of 92.5mmHg. A sample of about 150g in weight was heated by high frequency induction heating and the developing hydrogen pressure was measured by diffusing hydrogen into an evacuated palladium tube. The oxygen in samples was determined by the vacuum fusion technique.
The equilibrium constant for the reaction is expressed as :
log K0=log(PH2·a0⁄(PH2O))=−8594⁄T +1.956
This value is quite different from that obtained by Allen and Hewitt, but is in good agreement with the values calculated from the experimental results obtained by the electrochemical determination of oxygen in liquid copper or by the equilibrium measurements of the reaction of carbondioxide with liquid copper.
